Piston packing



J. F. FOEHR PISTON PACKING Dec. 19, 1933.

Filed Feb. 5, 1930 3mm M a' mm@ was Patented Dec. 19, 1933 UNITED STATESPATENT OFFICE 9 Claims.

This invention relates to a packing for pistons, plungers, rods and thelike, and particularly to a packing for use in connection with gasoline,oil, water, air or similar fluids, and it is an object of the inventionto provide a packing which is largely or Wholly impervious to suchfluids. A particular use for which these packings are designed is ingasoline or oil pumps where it has been very difiicult to preventleakage of the gasoline or oil past the packing as these materials veryreadily penetrate the fibrous materials ordinarily used for packings. Itis, however, to be understood that these packings are not limited tosuch use but may be used with water, steam, air or other fluids, and arenot limited to cup or rod packings, but are equally adapted forso-called U packings, V packings, flange packings and the like.

In the accompanying drawing, I have illustrated by way of example threedifferent types of packings, and have also illustrated an effectivemethod of making these packings to insure that they will be practicallyimpervious to the fluids with which they are to be used.

In this drawing Fig. 1 is a section of a cup packing constructedaccording to my invention of the type which are largely used forgasoline and oil service pumps and pistons such as are used with air,steam, water and the like.

Fig. 2 is a top plan view thereof.

Fig. 3 is a section of a flange or rod packing involving my invention.

Fig. 4 is a top plan view thereof.

Fig. 5 is a section of a U packing involving my invention.

Fig. 6 is a top plan view thereof.

Fig. '7 is a cross section through a die showing an effective method bywhich the U` packing may be made, and

Fig. 8 is a similar view showing a die illustrating an effective methodof making the packings shown in Figs. 1 and 3.

It has been proposed to make this type of packing of a plurality ofplies of fibrous material such as leather secured together by anintermediate layer of adhesive material impervious to air with which thepacking was to be used, but these packings have always had a certainarea which was not protected by the impervious material so that acertain amount of the air would always leak through the packing. Such aconstruction would be particularly objectionable for use in gasoline andoil service pumps as rendering the pumps inaccurate. I have overcomethese objections by so 55 constructing the packing that the layer ofimpervious adhesive material extends to the bearing surface of thepacking so as to engage the surface of the piston, plunger, rod or thelike with which the packing is used and over which the packing moves inuse, so that this impervious protecting layer extends entirely acrossthe area or passage to be protected by the packing and thus reduces theleakage of the fluid to a minimum as there is no unprotected portion ofthe fibrous material which can permit the fluid to pass through. e5 Thepacking remains sufficiently flexible to maintain a tight contact withthe surface of the cylinder rod or other member with which it is to beused.

Referring to the packing shown in Figs. l and 2, this is a cup or pistonpacking and may be built up of any desired number of layers or plies ofthe fibrous material. This is true in all the formsl of packings shownor described, but for simplicity in illustration they have all beenshown as composed of two plies only of the flbrous material. Thus, thepacking shown in Figs. 1 and 2 comprises a cup member 10 of anyvsuitable fibrous material such for example as leather and an inner cupmember 11 in nested so relation therewith of the same or any desiredflybrous material. These two cup members are secured together by anintermediate layer 12 of an adhesive material impervious to the fluidwith which the packing is to be used. Thus, for example, for use withgasoline, oil, water, air and the like a cement or adhesive material isused which is water and oil proof, such for example as a cellulosiccement comprising nitro cellulose dissolved in a suitable solvent suchas acetone. 90 This impervious material is applied so as to cover theentire opposed surfaces of the fibrous members and to thus provide acontinuous layer of this material between them. In this type of packingthe outer side surface 13 is ordinarily the 95 bearing surface and isthe surface which engages the surface of the cylinder with which thepiston employing the packing is to be used. It will be noted that theouter free edge 14 of the inner member 11 extends laterally over thefree edge 100 15 of the outer member 10 and the intermediate layer ofimpervious adhesive material 12 extends to the bearing surface` 13 asindicated at 16. Therefore, the .free edge of this intermediate layer ofimpervious material is exposed on the bearing surface 13 of the packingand engages the surface of the cylinder indicated diagrammatically at 17with which the packing is to be used. It will, therefore, be noted thatwith this construction there is no portion of fibrous material 11 whichis left unprotected by the impervious layer and, therefore, the leakageof fluid through the packing is wholly prevented or reduced to aminimum. The inner member 11 can be termed a liner or protector for thelayer of impervious material.

In Figs. 3 and 4 is shown how the same idea can be used with a'fiangeembracing a rod or plunger. In this construction, the packing comprisestwo or more nested members 18 and 19 which are secured together by theintermediate layer of adhesive impervious material 20 corresponding tothe layer 12 in Fig. 1. This packing, however, comprises a cylindricalportion 21 and a lateral flange portion 22 which flange portion isclamped between any suitable holding members to secure the packing inplace, and the cylindrical portion is openat its lower end forming apassage for the rod 23. It will be noted that in this construction, thefree edge 24 of the member 18 extends laterally over the free edge 25 of.the member 19 so that the free edge 26 of the layer of v,imperviousmaterial 20 is exposed on the bearing surface of the packing and engagesthersurface of the rod 23 relative to which the packing moves. Thus, theentire brous portion of the packing is protected by the impervious layer20 to prevent passage of fluid through this brous material the same asin the rst form.

In Figs. 5 and 6 is shown how this same construction may be employed fora U packing. This packing comprises outer and inner brous members 27 and28 respectively of substantially U shape in cross section and arrangedin nested relation. The two members are separated and secured togetherby the intermediate layer 29 of the adhesive material impervious to thefluid with which the packing is to ybe used. This layer corresponds tothe layers 12 and 20 of the rst two forms of the packing described. Itwill also be noted that the free edge 30 of the member 28 extendslaterally over the free edge '31 of the member 27 so that the free edgeof the impervious layer 29 is exposed as shown at 32 onthe outer bearingsurface 33 of the packing. In like manner the inner free edge 34 of themember 28 extends over the inner free edge 35 ofthe member 27 so thatthe inner free edge 36 of the impervious layer 29 is exposed on theinner bearing surface 37 of the packing. Therefore, these free edges 32and 36 of the impervious layer engage the surfaces of the piston, rod orother element with which the packing is to be used and relative to whichit moves. It will, therefore, be seen that in this packing as well as inthe other two forms the entire area of fibrous material is protectedbythe impervious layer to prevent passage of the fluid through thefibrous material.

In Figs. 7 and 8 is illustrated dies and a method of making the packingswhich is very effective in insuring that the layer of imperviousmaterial extends to the bearing surface entirely around the packing.Thus, in Fig. 7 which shows a die and method of making the U packing,the two plies of fibrous material 27 and 28 are placed one above theother with the liquid adhesive material 29 between them, and are placedon top of the spaced rings 38 and 39. A suitably shaped die member 40having an annular projecting portion 41 is pressed down on top of thesemembers forcing them downwardly between the rings 38 and 39. 'I'hisshapes the fibrous members into substantially the U shape and thepressure also evenly distributes the cementing material 29 throughoutthe entire space between the two fibre members. The bre members are madesufficiently large so that when thus formed they have lateral flangeportions 42 and 43. After the cement has set, the packing may be removedfrom the die and then by cutting them around their peripheries at thedesired size, usually on alignment with the cylindrical surfaces 33 and37 as indicated by the lines 44 and 45 respectively. It will benotedthat thus a continuation of the bearing surface is provided acrossthe free edges of the fibre member. This cut also extends across thelayer of impervious material 29 and thus insures that the free edges ofthis layer extend completely to the bearing surfaces of the packins.

In Fig. 8 is shown a similar method for making the packings of Figs. 1and 3. Here the nbre members 10 and 11 are placed in super-posedrelation on a ring die 46 with a layer of adhesive impervious material12 between them. The upper die member or plug 47 is then forceddownwardly shaping the packing as shown in Fig. 8 and leaving a lateralange portion 22. If, after setting, the packing is cut around itsperiphery as in'dicated by the line 48, this cut will cut through theimpervious layer 12 leaving its free edge exposed in and flush with theouter side surface of the packing, and I have vthe packing shown inFig. 1. If, however, instead of cutting on the line 48, we cut on theline 49 in alignment with the inner side surface of the packing, we alsocut through the impervious layer 12 and produce the packing shownin Fig.3 with a free edge of this impervious layer 12 exposed in and flush withthis inner surface. This method of making insures that the material ofthe impervious layer extends flush with the bearing surfaceof thepacking throughout its entire periphery.

It will be obvious that although I have illustrated only three differenttypes of packing, the same construction may be employed in numerousother types of packing, the free edge of the intermediate layer ofadhesive impervious material extending to and being exposed on thebearing surface of the packing in each case.

Having thus set forth the nature of my invention, what I claim is:

1. A packing of the character described cornprising two or more plies offibrous material secured together by a layer of adhesive materialimpervious to the fluid with which the packing is to be used, saidpacking having an outer bearing surface to engage and move over anothersurface, and said layer of adhesive material extending to the said outerbearing surface of the wall of the packing so as to engage the surfaceover which the packing is to move so that there is no fibrous materialforming a direct path from one side of the packing to the other.

2. A packing of the character described comprising two or more plies ofleather with a layer of adhesive material between adjacent plies, saidpacking having a bearing wall to engage and move over another surface,said layer of adhesive material being impervious to the fluid with whichthe packing is to be used and extending to the face of the bearing wallof the packing so as to engage the surface over which the packing is tomove so that there is no leather forming a direct path from one side ofthe packing to the other.

3.,A packing of the character described comprising a leather membercovered on one side with a layer of an adhesive material impervious tothe fluid with which the packing is to be used, said packing having abearing wall to engage and move over another surface, said layer ofimpervious material extending to the bearing surface of the packing soas to engage the surface over which the packing is to move and eliminateany direct path through the leather from one side of the packing to theother, and a protector for the impervious layer comprising a fibrousmember over said layer and secured to the leather member by saidadhesive material.

4. A packing for use with a cylinder or rod comprising two or more pliesof ilbrous material with the adjacent plies secured together by a layerof a cement impervious to the fluid with which the packing is to beused, said packing having a bearing surface to engage and move over thesurface of the cylinderpr rod, said layer of cement extending to thebearing surface of the packing so as to engage the surface of thecylinder or rod over which the packing is to move and there is no directpath through the fibrous material from one side of the packing to theother.

5. A packing for use with a cylinder or rod comprising two or more pliesof leather with 'the adjacent` plies secured together by a continuouslayer of cellulose cement, said packing having a bearing surface toengage and move over the surface of the cylinder or rod. said layer ofcement extending to the bearing surface of the packing so as to engagethe surface of the cylinder or rod over which the packing is to move andeliminate any direct path through the leather from one side of thepacking to the other.

6. A cup piston packing comprising two or more cupped members of brousmaterial secured together in nested relation by a layer of adhesivematerial impervious to the fluid with which the packing is to be used,the free edge of the inner member being extended outwardly over the freeedge of the outer member and in alignment with the outer surface of theouter member so that the edge of the layer of adhesive material isexposed on the outer bearing surface of the packing to engage thesurface of the cylinder with which it is used and there is no directpath through the flbrous material from one side of the packing to theother.

7. A packing of the character described comprising two or more membersof fibrous material in nested relation, the adjacent members beingsecured together by a layer of adhesive material impervious to the uidwith which the packing is to be used, a free edge of' one member beingextended laterally over a free edge of the next adjacent member andending in alignment with a longitudinal surface thereof to formtherewith a bearing surface and so that the free edge of the layer ofadhesive material is in said longitudinal surface to eliminate anydirect path through the fibrous material from one side of the packing tothe other.

8. The method of making packing of the character described comprisingcovering the surface of a ply of fibrous material with a layer of liquidadhesive material impervious when hardened to the uid with which thepacking is to be used, placing a second ply over the first ply andpressing the two plies together to distribute the liquid adhesivethroughout the opposed surfaces of the plies, and then cutting thepacking to shape on a line spaced from the edges of each of the pliesand across the layer of adhesive material to form a bearing surface toengage and move on the surface with which the packing is to be used andto eliminate any direct path through the fibrous material from one sideof the packing to the other.

9. The method of making a piston or rod packing comprising placing alayer of liquid adhesive material between two plies of fibrous material,pressing the plies together and shaping to form portions extendinglongitudinally of the center line and another portion extendinglaterally therefrom, and then cutting the laterally extending portion ona line forming an extension of the surface of the longitudinallyextending portion so that the edge ofthe layer of adhesive material willbe on a surface of the longitudinally extending portion and there is nodirect path through the fibrous material from one side of the packing tothe other.

JOSEPH F. FOEHR.

